Centrifugal pump



March 5, 1935. c. H. FERGUSON 1,993,268

'CENTRIFUGAL PUMP Filed Aug. 16, 1929 4 Sheets-Sheet 1 O @3 w an a. n {O N N n w w 8% R v a Q INVENTOR (7am 5 fi/fimauson/ ATTORNEY March 5, 1935. c H. FERGUSON 1,993,268

CENTRIFUGAL PUMP Filed Aug. 1-6, 1929 4 Sheets-Sheet 2 arch 9 c. H. FERGUSON 1,993,268 1 CENTRIFUGAL PUMP Filed Au g. 16, 1929 4 Sheets-Shet 3 INVENTOR CHARMSH FERGUSON ATTORNEY Ma rch 5, 1935. C FERGUSON 1,993,268

' CENTRIFUGAL PUMP Filed Aug. 16, 1929 4 Sheets-Sheet 4 INVENTOR C'HA EL 55 H Fbvcuks'o/v ATTORNEY Patented Mar. 5,1935

UNITED TATES A- JNT," OFFICE cim'rmrucn. rum

accompanying drawings which illustrate several embodiments of the invention selected by me for' "5 Purposes of illustration,

and the said invention is fully disclosed in the following description and claims.

My invention consists-in a portable self priming pumping apparatus of the centrifugal or .ro- 'tary type adapted particularly for handling heavily chargedliquids containing sand, gravel and other solid matter. Self priming centrifugal pumps asheretofore constructed have met with limited success when used for handling liquids containing considerable amounts of foreign matter. The small and frequentlynumerous passages ,for the passage' oi liquid soon become clogged, and whenscreens have been resorted to to pre-: vent foreign matter'from entering. the pump, it has been necessary to stop the operation of the pump at frequent intervals to'perrnit the cleaning of the screens. My invention overcomes these difficultiesand provides a self priming pump which can be used without screens and without danger of becoming cllgged by foreign matter in the liquid. Accordto my "invention I provide a pump w ch has but one suction and one discharge opening, the

discharge opening being of greater area than as to provide an; easy outlet fronrthe pump casg, and in connection with thepump I provide a priming reservoir which preferably surroimds the pump proper an'dinto which the liquid is discharged from the discharge opening'of, the pump. 1 also provide means for maintaining priming water in into thepump casing through the discharge opening thereof and discharged therefrom through the same opening together with air withdrawn from the suction aperture, as hereinafter described, so that should foreign matter be {present in the priming water it will enterand leave the pump casing through the discharge passage thereof without interfering in any-way with the priming action. Other objects of the invention include the provisionnfimeans for more eifectively sealing thepump shaft against lealrage' from or to the pump casing, means for preventing the loss of the primingliquid when the pump is at rest, and means for providing access to the interior parts of theapmtus for repair or replacement of worn parts. v

My'invention also'comprises the-novel features of construction and combination of parts herethe reservoir, which is drawn lliram Ferguson, N. Y L

929, Serial No. sacs!v inafter described the claims.

Referring to the accompanying drawings which illustrate several embodiments of the invention, Fig. 1 represents a vertical sectional view of a :pump embodying my invention, parts being shown in elevation.

2 represents a vertical sectional view on the line 2-2 of Fig. 1, parts being shown in elevation.

Fig. 3 is a detail sectional view illustrating the sealing means for connecting the in! preventing leakage around the impeller or pump shaft. p

Fig. 4 represents the parts shown in Fig. 3 iii "separated relation.

and particularly pointed out in impeller hous- .or pump casing to the pump body and for 5 is a vertical sectionalview or a pump embodying my invention showing a modification. Fig. 6 isa partial elevation of a pump embody: ing my invention showing a modification. 7

Fig.7 is-a section on line fl'1 of Fig.6. In Figs. 1, 2 and 3, I have illustrated the preferred form in which I have embodied my invention. In these figures 1 .representswhat 1 term 'the main frame or body of the apparatus, which is in the form of a hollow casting closed-at one end except for the necessary'aperture for, the

passage of the pump shaft therethrough and open f the suction opening andbeing extremely short so at the other end, and provided with an attaching flange -1*. This pump body; main portion of the priming reservoir; indicated at 2, and is preferably provided with a curved discharge, passage, indicated at 9, leading from the bottom of the reservoir to the upperpart of contains within it the R the main body and communicating with the discharge opening of the a paratus, 1, through I which the entire output of the apparatus is-discharged,,' In this instance the discharge aperture i 40 1 connectedby a nipple 15 to one end 01a 1" 16, the other endbeing provided with a detachable the T being connected with the main discharge pipe 18 of the apparatus, which may be of any I is provided with a suction inlet, indicated at ,4,- I

adjacent to the axis of the rotary impeller, which is indicated at 20, and is provided with a series of blades 21, which preferably do not extend to the inner periphery of the impeller casing, as

filling plug 17, and the central opening of let, indicated at 3. The impeller casing, 5, is provided on, the outer side the. outlet, 3, with a projecting wall or deflec 1', indicated at 10, to facilitate the discharge of liquid from the easing. This discharge outlet, 3, is the only outlet with which the impeller casing is ordinarily provided, and the pump or impeller casing is preferably so mounted that this outlet 3, is below the .axis of the impeller and preferably closely adjacent to the lower end, of the curved discharge passage, 9, although this is not absolutely essential, and the apparatus will work effectively with the discharge aperture in other positions if the discharge aperture is maintained below the level of the priming water in the reservoir. As will bemore particularly explained hereafter, the discharge aperture 3, from which the liquid and solid matter passing through the pump is discharged, also serves to admit priming water to 'the pump or impeller casing during the priming operation. The outer face of the body 1 is closed by an end plate, indicated at 25, provided with flanges which are clamped to the flanges 1 of the body 1 by bolts or screws, a packing .washer, indicated at 26, being employed between the flanges in order to make a tight joint. Within the end plate '25 is a space 27, separated by suitable partition walls. Thisspacej term the suction reservoir, and at the upper end of the same is the main inlet aperture 28 for the apparatus, here shown as screw threaded to receive a nipple 29, to which the usual uptake pipe 30 is connected. The inlet aperture 28 is preferably provided with a-valveseat, and in this instance I-have shown the nipple 29'extending intothe suction reser-. voir 27, and provided with a valve seat 31 at its lower end. This valve seat is adapted to-receive a floatable ball valve, indicated at 12, which may be formed of balsa wood or cork composition, or

any other suitable material. This ball valve will be easily pushed away from its seat by the incoming water when the pump is operating, and when the pump is stopped the ball valve will seat and prevent the water'within the pump.casing and reservoir being siphoned back-through the up take 30. The lower end of the suction reservoir 27 communicates with the pump or impeller O88!- ing, by the aperture 4 adjacent to the axis of the impeller, and as shown ,in Fig.2, the endplate,

25 is provided with annular flange portions, in-

dicated at 32, to engage the impeller housing, a.

suitable gasket, indicated at 33, being provided between the parts in order to make a tight joint. Thebodyloftbepumpissllnportedbymeans of a standard, indicated at 34, provided with a suitable base 35am! this standard and base may be castintegrally with .the body 1 or formed separately, as herein shown, and connected thereto in any usual'ordesired manner. The opposite face of the standard supports a suitable motor Y for 'drivingthe impeller, and in this instance I have indicated tically an electric motor 36, but it is to be understood that a gasoline engine or other type of motor may be employed."

37 indicates the impeller short, which may; be

formedintegrally with the motor shaft, or con'- .nected theretoinanydesiredway.

InFi88 .3 8-hd4,Ihave indicatedxneansfor insuring atlght joint between the impeller-Janus? ing and the main body; and between thekimpeller shaft'and the through which it passesfrom the impellert'o the motor. As showr'iinthis flg- 39 in the main body 1, which provided with a hub portion 1 surrounding this recess. This hub is provided with a sleeve of reduced diameter, indicated at 1 upon which the impeller housing 5 is fitted and secured in any desired manner, a packing washer, indicated at 40, being inserted between the impeller housing and the hub 1. The hub 1 is provided with a recess 41 separated from the recess 40 by an inwardly extending annular wall 1'. A reduced portion 37 of the pump shaft extends through the bearing 38 and through the recess 41 and is provided with a threaded portion 37 upon which the impeller 20 is secured, the impeller hub 22 extending into the recess 41. The impeller hub 22 is provided with a longitudinally locking groove or recess, indicated at 23, on its exterior, and the inner face of represents a similar metal sealing washer, which engages the washer 44, and has a projecting portion 47 extending into the groove 23in the hub of the impeller sothat it will rotate therewith. Between the metal sealing washer 46 and the impeller 47 I employ ayielding resistance member, indicated at.48. which in this instance is formed of molded rubber corrugated in crosssection. It will be seen that this member 48 exerts at all times a pressure against the washers 46 and 44 and the gasket 43 in a direction parallel to the axis of the impeller, which will make a very tight seal between the impeller shaft and the partsthrough which it extends, while the only surfaces in wearing oontact'are the adjacent surfaces of the metal sealing washers 44. and 46. The various partsjust described are shown in separated relation in Fig. 4, and it willbeseenthatbyhavingthepartsofthepump placement or repair of any of the parts of theapparatus. 7

Assuming that the apparatus hereinberure described is to be operated for the first time, the

reservoir 2 is fllled with liquid throughqhe opening provided by removing the cap 1'7, and the cap is replaced. The liquid will entertheimpeller'housing or pump casing through the dis-- "charge opening 3, and willstend to compress the air in the portion of the pump casing above the inlet aperture. The liquid is trapped within the reservoir and pump in communication with the discharge'aperture of thepump casing or impeller housing which it effectively seals.

The impeller is rotated in the direction of the arrow 41 in Fig. 1. The liquid within the pump casing will be thrownto the periphery and will bedischarged through the discharge opening 3 along the outer side thereof, and as the opening 3 is indirectcommunication withthe reservoir 2, liquid will be drawn into-the pump casing through the aperture v3 adjacent'to the inner side thereof and at the same time air will be ure, 38 represents the supporting bearing for the through the suction 'opening4 from the II messesy suction reservoir and uptake. Thus 'as the rotation of thejimpeller continues, the liquid being heavier than the air is forced outwardly toward theperiphery of. the pump casing or impeller casing and carried around what may be described as an outer channel therein, while the will be drawn in adjacent to the axis of the impeller and outwardly, against the wall or chan nel of water, the air being discharged along with the water through the discharge aperture 3'. The air will rise through the priming water either within the discharge passage 9, in which case it goes directly to the outlet pipe 18, orexterior to the passage 9, in which it will pass through the vent aperture 6, and proceed to the outlet pipe 18. This action con ues untfl the air is exhausted from the suction reservoir and uptake,

- whereupon liquid from discharge of water from the pump casing will completely fill the discharge opening the source of supply will rise in the uptake, filling the-suction chamber and the pump or impeller housing, and being discharged through the opening 3 into the reservoir 2. As soon as this condition exists the will continue to discharge into the reservoir 2 a stream having the cross section of the discharge aperture, 3. As soon as the reservoir 2 'is filled, a pressure will be created there- 3, and thepump in and the liquid will be forced out through the discharge passage 9-and the outlet pipe 18. Asthe discharge passage 9, extends to a: point near the bottom oi. the reservoir, it water is forced out through this discharge passage it will necessarily carry with it the heavier and other particles of in the liquid, so that there is no opportunity for sediment to collect in the reservoir or in the pump casing.

- During the priming operation, the projectin wall 10 of the pump or impeller casing, which 1 projects beyond the oute edge of the discharge valve 12, in which case that the pump can is lowered to that aperture 3, has the effect of carrying the water discharged through the aperture 3, together with the layer of air carried thereby beyond the inner edge of the discharge aperture 3, so that this air is prevented from reentering' the pump or impeller casing through' the discharge aperture 3, and is forced to find its way upward to the discharge pipe 18 eitherthrough or exterior to the discharge passage, as previously described.

As long as the pump is in operation, the water entering through the uptake 30 will push aside the ball valve 12 and render it ineffective. when the pump stops for any reason, theb'all valve 12 will instantly seat and prevent the water within the reservoir 2 and the reservoir 2'I- and within thepump casing from being iph ned out, thus trapping a quantity of the liquid within the reservoir 2,- the pump casing and reservoir 27, arid sealing the discharge opening of the pump, so

will prime itself .hi the manner previously-described, withdrawing the air from the uptake 30 andresumin pumping.

In some instances I may dispense with the ball it wouldbe desirable to provide other means for preventing the siphon.- ing of the water of the reservoir 2 and pump housing when the pump is stopped; This can be acsmall aperture at the casing to admit air siphoningacti'm when the water point! In order to save illusand break the or impeller will follow that as the.

foreign matter contained be started at any time and shown in m. 1, the impeller casingm'ovidcdwithsuchanopening,whichisindicatedat 5 0, and is shown closed by a plate 51 mm. 1, it beingunderstoodthatthisplatecan be removed in case lentisdispensedwlth. mm. 51 have shown a modified form of pumping apparatus embodying my present invention, in which the axis of the impeller is vertical instead of horizontal. In this parts corresponding to those shown in 2 are giventhe same the addition of 100, 101 represents the body, in the lower portion of. which is'formed a suction .pe servoir12'l separated from the upper portion I of the interior en agin a gasket dered portion of the cured in any usual or bolts. The plate'125 is provided tration I have Fi s. 1 and desired manner, as by with the suction the ball valve oriits equivafigure in-which thereference numerals with inlet aperture 104, registering with 9. correspond-.

ing aperture 104 in the pump casing or impeller housing 105, a suitable gasket 126 being provided to eflect a tight joint between the impeller housing and the plate 125. 103 represents the discharge aperture of the pumLcasin 105. ,and 110 the outwardly extending c to the outer edge of the upper end of the body'lol, and conveniently located in the side wall thereof, is a discharge aperture 101", to which the discharge pipe 118 is connected in any desired way. From the dis charge opening 101 a discharge passage 109 extends to a pointnear thebottom of the priming reservoir 102, which is formed within the main body above the plate 125, and this passage 109 is provided near its upper end with a vent aperture 10s. in thisinstance the body 101 .is closed at its upper end by a plate 134; secured thereto in any desired manner upon a gasket or washer 134, and in this instance the electric motor, indicated at 136, is supported on this plate 134 and has its shaft extending lindrical portion 137 surrounding the motor shaft, shaft and sealed in the manner previously described with reference to the preceding figures. In this instancethe suction reservoir 12'! is provided with an upwardly extending pipe 130', providedwith a 1' fitting is closed by acap ll'l'serving as a filling cap for the apparatus, and the central opening of the with the nipple 129 extending into the 'r and providing a seat 131 for the fioatabie ballvalve- 112. The interior of the T is providedwith a deflector 130 to guide the ball in its moveratus will be exactly the same asthatpreviously described, and the operatic need not be repeated. hodiment of my invention, in which the, parts corresponding to those in'Figs, I to 4' inclusive are given the same reierencenumerals addition of 200., In

through a depending cy-i not shown, which is connected to the impeller w h this modification 205-repre- 130 at itsupper end, which In Figs. 6 and '7 I have illustrated asimple emsents the pump or impeller casing having the inlet 204 adjacent tothe axis of the impeller 220, and connected with the uptake 230 through a T casting 230 constructed and operating exactly like the one illustrated in Fig. 5, in connection with the uptake and provided with the mu valve ,the lower end ,of a'closed reservoir e opening 203 is connected to. 7 2oz, said reservoir being in thisinstance vertically I aperture to conduct the discharge water and air. during a floatable ball the reservoir to deliverthe priming operation along the path indicated by the-arrow, r, in Figure 7, and out of the path of the incoming water, indicated by the arrow 1! in that figure, pensed with if desired. The operation of this form of apparatus will be substantially as hereinbfore described. If the pump stops, water will be trapped by the closing of the valve 212 within the reservoir and pump casing, and as soon as the pump is again Started, water will be drawn in along the lower or inner side of the discharge aperture 203 and discharged along the upper or outer side thereof, together with air withdrawn from the uptake, which air escapes through the vent aperture 206 and discharge pipe the air is exhausted and the pump is ,in full operation, when the water will be discharged from the bottom ofthe reservoir through the passage 209 and outlet pipe 218, carrying sediment or heavy particles.

Patent is:-

'l. A pumping apparatus comprising. a reseryoir,'a rotary pump having a rotor provided with a. horizontal axis and a casing provided with a tangential discharge aperture communicating tion aperture out of communication with said reservoir, the outer wall of said discharge apertlu'e being extended projecting to a point adjacent to the bottom of the air carried by the discharged liquid out of contact with the entering liquid and to prevent the accumulation of sediment.

2.'A pumpingapparatus comprising a reservoir, a rotary pump having its casing provided withatilngential discharged liquid out of: contact with the enteringv liquid.

1 3. Amimpingapparatua comprisingareservoir,

arotarypump wlthanhfletapertmeavalveseattherefonand valve forsaidseat.

El- Er s a d a ge of the discharge although the part 210 may be dis--" 218, until.

with it any What I claim and desire to secure by Letters beyond the other wall and I tion extending to apoint n e rwervoir for insuring the discharge of solid matter therefrom during pumping, an inlet reservoir afloatable valve in de$aemiiymmmtedinsaidbodyandhav-- .reservoir being provided with a discharge outlet at-its upper end.

5. A pumping apparatus comprising a main body forming a priming reservoir, a rotary pump casing detachably mounted in said body and having a discharge andvpriming aperture communicating with the bottom portion of said reservoir, and forming the only communication between the pump casing and reservoir, said main body being provided witha detachable; end plate provided with a suction reservoir out of communication with the priming reservoir and communicating with the suctionaperture of the pump casing, said priming reservoir having a discharge outlet adjacent to its upper end, and a discharge passage extending therefrom to a point near the bottom of the priming reservoir.

6. In a centrifugal pumping pparatus, the combination with a centrifugal pump comprising a circular pumpcasin jacent to, the axis of the impeller, and a single discharge peripheryof said pump casing, of a rotary impeller freely revoluble on a horizontal axis in said casing, and a priming reservoir surrounding thepump casing, in communication with the said discharge and priming aperture of the pump casing and outr of communication with the inlet of said casing, and a main discharge passage for theapparatus directly connected at all times with said reservoir and receiving the pumped water directly therefrom during the pumpingoperation, an inlet reservoir communicating with said axial inlet aperture of the pump casing and extending above. the same, and providedwith an inlet aperture above said axial inlet aperture.-'

said last named aperture being provided with a horizontal valve seat, and a floatable valve in said peller freely revoluble on a horizontal axisinraid casing, and a priming reservoir Surrounding the pump casing, in communication with the ,said dischargeandprimingapertureofthepumpcasing and out of communication with the inlet of said casing, and a main discharge e for tbeapparatusdireetlyconnectedatalltimea with saidreservoir and receiving the pumped water direc ly eration, said having a. porbottom' of said havinganaxialinlet ad--' and priming aperture adiacentfto the therefrom during the pumping 09- communicating with said axial inlet aperture of the pump casing and extending above the same,

and'provided with an inlet aperture above said axial inlet aperture, said last named aperture being provided with a horizontal valve seat, and

said inlet reservoir forengag --a.rnla pumping M the combination with a centrifugal pump comprising a'circularpumpcasinghavingan axialinlet adjacent to the axis of the impeller, and a single to periphery of mid pump ing to a point near the bottom of said reservoir for insuring the discharge of solid matter therefrom during pumping,and being provided with an air outlet adjacent to the upper end of the said reservoir and communicating therewith, an inlet reservoir communicating with said axial inlet aperture of the pump casing and. extending above the same, and provided with an inlet-aperture above said axial inlet aperture, said last named aperture being providedwith a horizontal valve seat, and afioatable valve in said inlet reservoir for engaging said seat..

9. In a centrifugal pumping apparatus, the combination with a centrifugal pump comprising a circular pump casing having an axial inlet adjacent to the axis of the impeller, and a single tangential discharge and priming aperture adjacent to the periphery of said pump casing, of a rotary impeller freelyrevoluble in saidcasing, and a priming reservoir surrounding the pump casing, in communication with the said discharge and priming aperture of the pump casing. adjacent to the bottom of said reservoir, said reservoir being out of communication with the inlet of said casing, and-a main discharge passage for the apparatus directly connected and in'open communication at all times with said reservoir and receiving the pumped water directly therefrom during the pumping-operation, said discharge passage having a portion extending to a point near; the bottom of said reservoir for insuring the discharge of solid matter therefrom dur-' ing pumping, the tangential discharge aperture of the pump casing discharging in a direction toward the lowerend of said discharge passage, toassist in delivering solid matter from said.

' reservoir. 1

10. In a. centrifugal pumping apparatus, the combination with a centrifugal pump comprising a. circular pump casing having an axial inlet adjacent to the axis of the impeller, and a single tangential discharge aperture adjacent to the periphery of said pump casing. of a rotary peller freely revoluble in said casing, and a p 1 mg reservoir surrounding the pump casing, in

' communication with the said discharge aperture of the pump casing and out 'of communication with the inlet of said casing, and a main discharge of solid matter therefrom during pumping,

the tangential discharge aperture being located adjacent to the lower part of the pump casing and discharging'in a direction toward the lower end of said; discharge passage, and being provided with a deflector extending from the outer edge portions only of said discharge aperture and "projecting toward said discharge passage, to permit the admission of water from ,said reservoir tothev pump casing adjacentto the inner edge,

of said-aperture and to facilitate the discharge of 'entrair'i'ed air from the pump casing during Priming.

l1. In'a centrifugal pumping apparatus, the combination with a centrifugal pump comprising a circular pump casing having an axial inlet adjacent'to the axis 'of the impeller, and a single tangential'discharge aperture adjacent to the periphery of saidpump casing, of a rotary impeller freely revoluble in said -casing, and a priming reservoir surrounding the pump casing, in communication with the said discharge aperture of the pump casing and out of communication with the inletof said casing, and a main discharge passage for the apparatus directly connected at all times with said re'servoir'and receiving the pumped water directly therefrom during the pumping operation, said discharge passage having a portion extending to a point near the bottom of said reservoir for insuring the discharge of solid matter therefrom during pumping and being provided with arr-air inlet adjacent to the upper end of the saidreservoir, the tangential discharge aperture being located adjacent to the lower part of the pump casing and discharging in a direction toward the lower end of said discharge passage, and being provided with a ,de-' flector extending from the outer edge portions only of said discharge aperture and projecting toward said discharge passage, to permit the admission of water from said reservoir to the pump casing adjacent to theinner edge of said aperture and to facilitate the dischargeof entrained air-from the puinp casing to the airoutlet adjacent the upper end of the said reservoir during priming. 4 4

12. In a pumping apparatus; the combination with a reservoir provided with a'discharge ad-' jacent to its upper end and a discharge passage leading therefrom to a point near the-bottom of the reservoir, of a rotary pump havingits casing provided with a tangential dischargeiaperturecommunicating with said reservoir anddischarging in a direction toward the lower end of said discharge passage to' facilitate the delivery of entrained solid material during pumping, and adapted to receive priming liquid from and to discharge it together with air into said reservoir during priming,-said pump casing having a suction' aperture out of communication with said reservoir, the outer wall of said discharge aperture being extended beyond the other, in a directiori toward said discharge, passage, to deliver the air carried by the discharged water during priming clear of the entering liquid. 13. In' a pumping apparatus, the combination with a reservoir provided with a discharge adjacent to its upper endand a discharge passage leading therefrom to a point near the bottom of the reservoir, of a rotary'pump having its .088?

ing provided with a'tangential discharge aperture communicating with said reservoir and discharging in a 'direction toward the lower end of said dischargepassage to facilitate the delivery of entrained solid materialdurlng pumpin and adapted to receive priming liquid from and to discharge it together withair into said reservoir during priming, said pump casing having a sucervoir, the outer wall'of said discharge aperture being extended-beyond the other, in a direction toward said dischargepassage, to deliver the air carried by the discharged waterdurlngpriming clear of the entering liquid, and to facilitate the delivery of solid matter during pumping, said discharge, passage being providedjwith an aperture tion aperture out of communication with saidwesv adjacent to the upper partof said reservoir com municating therewith to facilitate the discharge.

of air from said reservoir during priming.

' 14. A pumping. apparatus comprising a liquid reservoir provided with a discharge. adjacent to its upper end and having a discharge passage extending therefrom to a point adjacent to the bottom 01' the reservoir, said discharge passage being separated from the reservoir throughout its entire length and having an inlet communicating with said reservoir at a point adjacent to the bottom of the same to insure the discharge of entrained solid matter, a pump casing'located in said reservoir provided with an axial inlet' aperture out of communication with the reservoir,

and a-tangential discharge aperture communicat- 7 ing with the reservoir adjacent tothe lower end thereof and adjacent to the inlet oi'said dis-' charge 1 e, and a rotary impeller in said pump casing, said reservoir being provided with an air vent aperture communicating with said discharge said 0': il

passage adjacent to the upper end or 15. A pumping apparatus comprising'a liquid reservoir provided with a discharge adjacent to its upper end and having a discharge e extending therefrom to a point adjacent to the bottom or the reservoir, said discharge e being separated from the reservoir throughout itsentire length and havingan inletcommuni cating with said reservoir at a point adjacent to the bottom or the same to insure the discharge of entrained solid'matter, a pump casing located in said reservoir provided with an axial inlet apert'ure'out or communication with the reservoir, and a tangential discharge aperture communicating with the reservoir adjacent to the lower'. end thereof and a deflector at the lower edge oi! saidaperture forming a continuation of the wall or the pump casing and directed toward 

